Coating compositions containing certain ethylene copolymers and wax mixtures



United States Patent 3,338,856 COATING COMPOSITIONS CONTAINING CER- TAINETHYLENE COPOLYMERS AND WAX MIXTURES Karekiu G. Arabian, Walnut Creek,and Robert G. Lutz, Berkeley, Calif., and George A. Martin, Houston,Tex., assignors to Shell Oil Company, New York, N.Y., a corporation ofDelaware No Drawing. Filed July 29, 1965, Ser. No. 475,892 11 Claims.(Cl. 260-28.5)

This application is a continuation-in-part of applicants applicationSer. No. 388,320, filed Aug. 7, 1964, and now abandoned.

This invention relates to wax-containing coating com positions andparticularly to wax coating compositions containing polymericmaterials,which compositions have superior physical properties as wellas appearance.

Petroleum-derived waxes have been used for many years to coat paper andcarton boards especially for use in wrapping and containing dairyproducts and other food products such as bakery goods as well as forcoating cloth, fibers, and food products including cheese and meats torender them moisture-vapor resistant. Such waxes, however, have anunfortunate tendency to crack and peel off the coated articles,especially when they are subjected to repeated flexing or severecreasing. Even waxes modified with polyethylene, while having someimproved properties, show disadvantages relative to brittleness and lackof tensile strength particularly under low-temperature conditions.

In the last few years, the disadvantages which are normally attendant tothe use of wax in coating applications have resulted in the significantsupplanting of wax alone by the use of polymeric coatings, polyethylenein particular. However, despite the wide use of polyethylenecoated paperfor a wide variety of packaging uses, such laminates have not been apanacea since they too lack many important properties. For example,polyethylene coatings lack the desired resistance to penetration byoxygen, organic vapors and water vapors and; in addition, are veryexpensive. As a result, there has been considerable interest in theincorporation of polymeric materials into wax for the purpose ofbenefitting from the most desirable properties of both. Thus, polymerssuch as ethylene-propylene copolymer, ethylene-vinyl acetate copolymer,ethylene-ethyl acrylate copolymer, various synthetic rubbers and thelike have all been proposed for incorporation into wax.

Though many such polymeric materials have been used for blending withwax, with widely varying degrees of success in an attempt to enhancetensile strength, elongation, sealing strength, grease resistance and,at higher concentrations, even water vapor permeability, the addition ofcopolymers to wax gives rise to some detrimental effects as well. Themost serious of these is phase separation which occurs in both theliquid and solid phases of the mixture. Liquid-phase incompatibility ismanifested by the appearance of two distinct phases during moltenstorage. On the other hand, solid-phase separation gives rise to aparticular gloss instability, known as a bloom,

on the surface of the wax film.

It has now been found that the problem of poor gloss stability and otherfilm degradation, including blooming, can be reduced substantially byproper selection of a combination of certain distillate and residualwaxes in selected ratios without degradation of the other properties.

3,338,856 Patented Aug. 29, 1967 More particularly, it has been foundthat gloss-stable wax compositions containing as much as 50% by weightcopolymer are produced by selection, as the wax component, of a mixtureof waxes consisting of (a) a distillate paraflinic wax having a meltingpoint of at least F. and which contains no more than about 30% by weightnon-normal paratfins, and (b) a residual wax, the weight ratio of (a)and (b) each to the other being from 0.721 to 1.4:1. The foregoingcomposition when mixed with copolymer may be extended, without detrimentto its properties, with up to 25% by weight and preferably wit-h from 5to 15% by weight of the total wax component of distillate paraflinic waxhaving a melting point of at least F. and which contains at least about40% by weight of non-normal paraifins. A still more preferred range forthis higher melting distillate parafiinic wax is about 10-15% by weight.

The waxes which may be used in accordance with the invention, and whichare preferred, are petroleum waxes derived from the refining of waxylubricating oil base stocks. By the term distillate wax is meant thosewaxes which are derived from the refining of distillate lubricatingoils, while the term residual wax refers to those waxes which areremoved during refining of residual lubricating oils such as brightstock. The distillate waxes are generally paraflinic in nature, theratio of normal-toisoparafiins in which is inversely related to theirmolecular weight. The residual waxes, on the other hand, may containmicrocrystalline wax or high-melting-point paraffins or both. Virtuallyall residual waves are constituted of a mixture of both microcrystalline(amorphous) and paraffinic waxes; however such waxes can be furtherrefined (split) to produce separate wax fractions which are essentiallymicrocrystalline and essentially paraffinic (crystalline) in character.To be used in the coating compositions of the invention, the waxes mustbe rather highly refined, i.e., they should contain no more than about2.0% by weight oil and preferably 1.0% by weight or less.

The polymers which can be used in accordance with the invention can becharacterized in a general way as longchain hydrocarbon back-bones whichare randomly and irregularly substituted with side chains which are nomore than about three atoms in length. More specifically, the polymersare copolymers of ethylene with terminally ethylenically unsaturatedorganic compounds containing 3-5 carbon atoms. The preferred comonomersare selected from the group consisting of alpha-olefins, esters ofterminally ethylenically-unsaturated monocarboxylic acids and saturatedaliphatic alcohols and esters of saturated monocarboxylic acids andterminally ethylenically-unsaturated aliphatic alcohols. Examples ofsuch comonomers are unsaturated esters such as vinyl acetate, ethylacrylate and methyl acrylate and normal lower alpha-olefins such aspropylene, butene-l and pentene-l.

The ethylene-vinyl acetate copolymers which are to be used in thecompositions of the invention correspond to the general formula gainedby the combination of several different degrees of high and low densityand/or high and low molecular weight insofar as increase inlow-temperature properties without a corresponding increase inbrittleness being experienced.

The mole ratio of ethylene to higher alkene in the copolymer can bevaried from as low as about 60% to as high as about 95% (molar basis).However, more highly crystalline copolymers, i.e., those having from 80to 95% TABLE I.PROPERTIES OF ETHYLENEVINYL ACETATE GOPOLYMER S A B C D EF G H I J Wt. Percent Vinyl Acetate 33 28 28 23 23 18 18 Cf/VinylAcetate Mole Ratio 6.6/1 8/1 8/1 10/1 10/1 14/1 14/1 Melt Index, g./l0min 25 25 15 400 100 2 150 Molecular Weight 28, 000 28, 000 33, 000Softening Point (R and B), F 243 2 276 Tensile Strength, p.s.i 1,000 1,000 2,000 Elongation at Break, Percent 700 700 750 Theethylene-alpha-olefin copolymers which may also ethylene are preferredin order to avoid excessive tackibe used 111 accordance with theinvention have the general 35 new linear configuration Typicalproperties of ethylene-propylene copolymer as (OH) g well as some otherunsaturated ester copolymers are as n R follows:

TABLE IL-PROPERTIEIS OF OTHER ETHYLENE COPOLYMERS Ethylene/ethylacrylate Ethylene/methyl acrylate Ethylene] copolymers copolymerspropylene copolyrner Sample K L M N O Wt. Percent Comonomer 17.4 23. 618 Melt Index, g./l0 min 18 18 3. 5 6.6 1 15 Molecular Weight 32,00041,00 38,000 200,000 Tensile Strength, p.s.i 1, 200 750 180 1, 200 3,500 Elongation at Break, Percent. 700 800 710 763 570 Density 0. 927 0.932 0. 942 0. 947

1 Measured in 30% concentration with 180 F. residual paraffinlc wax.

wherein n is an average integer between about 10 and about (preferably10-40), R is a hydrocarbyl radical having l-3 carbon atoms and the unit(CH is an unbranched hydrocarbon chain, the average molecular weight ofthe copolymers being between about 20,000 and 800,000 (preferably200,000-400,000). Expressed as intrinsic viscosity (expressed asdeciliters/gm.), copolymers having intrinsic viscosities of betweenabout 1.0 and 3.0 are preferred. Intrinsic viscosity is determined indecalin at 150 C.

The density of the copolymers may be varied over a considerable range,usually between about 0.85 to about 1.0, low density copolymers beingregarded as those having densities in the order of 0.85 to about 0.91and high density materials being regarded as those having densities fromthe latter upper limit to about 1.0. Advantages are EXAMPLE I A largenumber of blends of ethylene-vinyl acetate copolymers with individualwax fractions was prepared in order to determine the effects of relativepolymer concentration and type of wax on the properties of the coatingproduced therefrom. The results are given in the following table.

TABLE III.PROPERTIES OF WAX-OOPOLYMER BLENDS Wax-Oopolymer BlendProperties Oopolymer Wax Blend Brookfield Sealing Water vapor No.viscosity strength 4 permeability Liquid Gloss (cp.) (g./m.) (g. /l001n./24 hrs.) compaticharacteristics bility tempera- Pertent Type 1 PercentDescription 210 F. 240 F. 75 F 85 F. Flat 2 Greased 2 ture, F.

100 124-126 F. M. 130/0 191/0 2.2 5.9 Gloss-stable, A11 2 F 98 P.,parafiim'c. 130/64 176/0 3. 2 7. 0 150 polymer bl nd 5 95 12.2 9.8137/82 193/86 3. 9 5. 7 bloomed Within 10 90 46. 4 32. 7 170/129 240/1223. 6 7. 5 30 Seconds at 80 568 434 4 OFT OFT 1.0 3.0 73 F. 3, 950 2, 470OFT OFT 0.8 0.9

2 A 98 124126 F. M. 150-175 All polymer 5 95 P., parafiinic. blendsbloomed 10 90 Within 30 sec- 20 ends at 73 F. 30 70 0 100 141-143 F. M.Gloss-stable. All 2 F 98 P., paratfinic. 150-175 polymer blends 5 95bloomed within 10 30 Seconds at 20 80 73 F. 30 70 30 70 30 70 50 50 5545 60 40 0 100 141-143" F. Gloss-stable. All 2 E 98 P., paralfinic.polymer blends 5 bloomed within 30 seconds at 73 F.

2 E 98 141-143 F. 6 113/73 138/92 0. 7 4. 4 All polymer 5 95 P.,paraffinlc. 12 168/127 188/137 1. 5 5.1 blends bloomed 10 90 42 4 OFTOFT 1.3 6.3 Within 30 20 80 315 OFT OFT 0. 1 4. 3 seconds at 73 F.

30 70 1, 928 OFT OFT 0. 1 1. 0

30 70 1,853 0 158-162 F., M. 160/0 0.2 5.1 Gloss-stable. All 2 F 98 P.,paraflfinlc. 268/134 1. l 4. 5 200-225 polymer blends 5 95 21. 2 17.0OFT OFT 0.9 7. 8 200-225 were gloss-stable 10 90 82. 9 60. 4 OFT OFT 1.4 9. 2 200225 at 73 F,

20 80 1,060 633 OFT OFT 0. 5 2. 5 bloomed at 30 70 7, 460 4, 090 OFT OFT0. 7 1. 1 175 about 93 F.

5 A 95 l58162 F. 196/98 235 Gloss-stable at 5 95 P., parafiiinlc. 73 F.bloomed at about 93 F.

0 100 F. M.P., 39/11 57/0 0.6 9. 7 Gloss-stable. All

2 F 98 residual polymer blends 5 95 paraflinic. .9 were gloss- 10 90 .3300 stable even 20 80 2, 050 650 OFT OFT 0.8 3. 2 225-250 after 24hours.

30 70 8, 250 5, 410 OFT OFT 0.9 l. 1 225-250 10 E 90 180 F. M.P., AllWere gloss- 20 80 residual stable.

30 70 parafiinic.

0 F 100 136.5 F. M.P., All were gloss- 2 i 98 residual microstable. 5 95crystalline.

1 Refer to Table I.

2 Coated on one side of paper except as otherwise indicated.

3 Lowest temperature at which polymer and wax formed single phase. 4 OFTdenotes complete fiber tear (perfect seal).

The foregoing data (Table III) show quite graphically of the mixtureinto separate liquid phases will result (1) the difliculties which areencountered in blending copolymers into wax. For example, the blendingof small amounts of copolymer (up to 15% by weight) tends to increasewater vapor permeability. On the other hand, the

in coatings having uneven thickness and properties, (2) in difficultiesin coater operation, and (3) separation in hot tank storage. For thisreason, one requirement of practical wax-polymer blends is that they bemiscible at least use of large amounts of copolymer (above about 50% 65down to the temperature at which they can be stored and by weight)raises the viscosity of the blend beyond the applied to the substrate.In many instances this is about useful viscosity range in most existingcoating apparatus. -210" F.

Likewise, the addition of copolymer in small concentra- The data inTableIII clearly show that no one type of tions in some instances mayalso reduce sealing strength. wax component is suitable. Blends 1-11show that, while But even more importantly, the incorporation of 00- 7low-melting-point paraflinic (distillate) wax results in polymer intowax raises the problems of liquid phase compatibility and poor glosscharacteristics.

Liquid phase incompatibility is a serious problem in that if the wax andcopolymer are not compatible (miscible) at blends of suitablecompatibility (compatibility temperature below about 190 R), such blendsare wholly unsuitable because of their poor gloss stabilitycharacteristics. Though the higher-melting-point (l41143 P.)

application conditions, the resultant separation 75 parafiinic(distillate) waxes when blended with the copolymer (Blends l23l) arealso sufficiently compatible, they likewise give coatings having poorgloss retention. However, the higher molecular weight paraffin wax isseen to require somewhat less polymer (15% versus 20%) to effectcomplete fiber tear on a sealing strength test.

The still higher (158162 F.) melting-point parafiinic (distillate) waxeswhen blended with polymer yielded coatings of very good gloss stabilityat 73 F.; however EXAMPLE II A series of wax-copolymer blends wereprepared which illustrate the effect of blending with different waxtypes and particularly the importance of the limitations in thecompositions of the invention. The composition and properties of theseblends are given in the following table:

wax for the lower melting material failed to improve gloss stability byany significant amount even though, as shown in Table III, the highermelting distillate wax alone had greater bloom stability than the lowermelting wax. On the other hand, from blends 62, 65 and 66, it appearsthat, when the b/ a ratio is within the afore-mentioned limits of 0.7:1to 1.4:1, the addition of at least 5% by weight of higher (150 F.)melting-point wax has a beneficial effect on gloss stability, whicheffect is, quite surprisingly, not present when the relative proportionsof residual and 150 F.-melting-point waxes are outside theabove-mentioned limits.

In addition to the foregoing discussed limitations regarding ratio ofdistillate and residual waxes, it has also been found to be important toexclude very low-molecular-weight parafiinic waxes, i.e., those having amelting point below about 135 F. This important additional limitation isillustrated in the following example.

EXAMPLE III Two wax-polymer blends were prepared, each containing 15% byWeight copolymer. The base composition, selected because of its knownsatisfactory properties (Blend 59, see Table III), contained equalamounts of residual wax and 135 F.-150 F. distillate paraflinic wax and12.1% by weight of 150 F. distillate parafiinic wax. In the other blend,half of the 135 F.150 F. dis- TABLE IV.PROPERTIES OF MIXED WAX-POLYMERBLENDS Composition, percent wt. Blend Properties Blend BrookfieldSealing Gloss No. Polymer 141143 F. 158l62 F. 180 F. 136.5 F. viscositystrength 1 stability 2 at Liquid (Sample .P., M.P., M.P., M.P., resid-Ratio, (cp.) (g/in) 110 F., 24 hrs Compati- F in distillate distillateresidual ual micro- BIA bility Table I) parafifinic paraflinicparaflinic crystalline Tempera- 210 F. 240 F. 75 F. 85 F. Initial Finalture, F

5 40. 7 13. 6 40. 7 1. 22 16 75 75 200 40. 7 13. 6 40. 7 1.0 74 70 36. 412.1 ea. 20. 5 ca. 16 1. 0 260 I93 CFT CFT 77 77 185 15 36. 4 12.1 ea.20. 5 ea. 16 1.0 75 75 15 25. 7 8.7 25. 7 24. 9 2. 0 85 75 20 34. 3 11.4 34. 3 1. 0 884 525 CFT CFT 75 60 190 20 34. 3 11. 4 34. 3 1. 6 80 2020 22.9 11.4 11.4 34.3 2.0 83 35 30 10 30 1. 0 6,850 3, 780 OFT OFT 19030 35 1. 0 78 46 l OFT denotes complete fiber tear (perfect seal).

Each of the wax copolymer blends was found to be stable with regard toblooming in that none bloomed even after extended storage at 73 F. Thisis particularly noteworthy in view of the fact that, as shown in TableIII, Blends 12-3 1, the paraffinic waxes having a melting point belowabout 150 F. were particularly susceptible to blooming, whereas thepresent blends were bloom-stable with as high as 40.7% by weight of141-143 F. melting-point paraflinic wax.

In addition, it is shown by Blends 57 and 58 that the two types ofresidual waxes, high-melting-point parafiinic and microcrystalline, maybe used interchangeably without significant reduction in gloss stabilityof the blend. It was particularly interesting and quite unexpected tonote that when the ratio of residual wax to paraffinic wax having amelting point below 150 F. (b/a) became too large, the gloss stabilityof the blend at the same copolymer levels was seriously degraded to anunacceptable level despite an initially higher gloss (reflectance). Forthis reason, the composition of the invention is limited to b/ a ratiosnot exceeding about 1.41 and preferably ratios of about 1:1. Blends 63and 64 also show that 150 F. melting-point paraffinic wax is notequivalent to lower melting-point paraflinic waxes in that substitutionof that 2 Oven test with hand-dipped cardboard specimens.

tillate parafiinic wax was substituted with l24-l26 F. melting-pointdistillate parafiinic wax. The blend containing the low-melting wax wassatisfactory in that it had no blooming tendency at 73 F., but bloomedseverely at below 105 F. The base composition was found to be stable atthat temperature. In addition, the low-melting waxcontaining compositionhad a very low blocking temperature (102 P.) which further excluded itfor use in coating materials which would be rolled or stacked.

Thus the blending of copolymer with the mixed wax blends of theinvention results in wax-polymer mixtures having commercially desirableliquid (molten) compatibility 200 F.) and which are stable to glossdeterioration, including blooming at temperature of 105 to 123 F.depending on the amount of polymer in the blend. Furthermore, each ofthe wax-copolymer compositions of the invention have excellent sealingstrength and grease resistance.

EXAMPLE IV of the properties of three further wax-copolymer blends.

TABLE V.PROPERTIES OF WAX-COPOLYMER BLENDS Composition of Blend, percentwt. Blend Properties Blend Type of copolymer and A B No. concentration158-162 F. M. Compatibility P., mixed Ratio, Gloss retention at 73 F.temperature 141-143 F. M. paraifinic wax 172-182 F. M. B/A F.)

P., distillate P., mixed paraflinic wax residual wax 67 30%ethylene/ethyl acrylate copoly- 3O 10 30 1/1 No bloom after 24 hours 210mer (Sample L in Table II). at 73 F. 68 30% ethylene/methyl acrylatecopol- 30 10 80 1/1 do 210 ymer (Sample M in Table II). 69 5%ethylene/propylene copolymer 40. 7 13.6 40. 7 1/1 do 190 (Sample inTable II).

In addition, it has been found that coatings of outstanding propertiescan be produced by application of the following compositions to variousfibrous substrates. In these coatings it will benoted that it ispreferred to use highmelting residual parafiinic wax at higher polymercontents in place of microcrystalline or mixed microcrystal-.

line and paraflinic residual wax.

TABLE VI.OOMPOSITION AND PROPERTIES OF PREFERRED WAX COPOLYMER BLENDSBlend No.. 70 71 72 73 Composition, percent by weight:

Ethylene-vinyl acetate copolymer -17. 5 5 17. 5-35 141-143 F. M.P.,parafilnic distillate wax -45 40. 7 36. 4 25-35 34. 3 30. 0 158-162 F. M.P., paralfinic distillate wax 10-15 13.6 12.1 10-15 11. 4 172-180 F.M.P., mixed residual wax 35-45 40. 7 36. 4 183 F. M.P., paralfinie lresidual wax 25-35 34-3 30. 0 Properties:

Bloom at 73 F None None N one None None None Compatibility temperature,F 200 200 190 190 190 190 Brookfield viscosity, cps.:

210 F- 22 260 884 6850 240 F 16 193 525 3780 Blocking temperature, F?5110 120/123 111/115 100 104/106 102/105 Sealing strength, g./in.

75 F"- OFT OFT OFT CFT CFT CFT 85 F. CFT CFT CFT CFT OFT CFT Greaseresistance, days 3 .1 3 30 30 30 30 30 Grazing with Dry Ice None NoneNone None None None 1 Type F, see Table I. 2 With waxed sulfite paper. 8Days for peanut oil to penetrate 1 ml. thick film.

We claim as our invention:

1. A polymer-containing wax coating composition consisting essentiallyof 550% by weight of a copolymer of ethylene and a C comonomer selectedfrom the group consisting of esters of terminally ethylenicallyunsaturated carboxylic acids and saturated aliphatic alcohols and estersof saturated monocarboxylic acids and terminally ethylenicallyunsaturated aliphatic alcohols said comonomer representing 17.4-30% byweight of the copolymer when the comonomer consists of esters ofterminally ethylenically unsaturated carboxylic acids and saturatedaliphatic alcohols and 18-33% by weight of the copolymer when thecomonomer consists of esters of saturated monocarboxylic acids andterminally ethylenically unsaturated aliphatic alcohols, and 95-50% byweight of a mixture of petroleum wax consisting essentially of (a) adistillate paraflinic wax having a melting point of 135-150 F. and whichcontains no more than about 30% by weight non-normal parafiins and (b) aresidual petroleum wax, the weight ratio of (a) and (b) each to theother being from 0.721 to 14:1, and (c) -15% by weight of distillateparaflinic wax having a melting point above 150 F. and which contains atleast about by weight of non-normal parafiins.

2. The composition of claim 1 in which the weight ratio of a and b eachto the other is approximately 1:1.

3. The composition of claim 1 which contains 5-35% by weight of thecopolymer.

4. A polymer-containing wax coating composition consisting essentiallyof 5-50% by weight of ethylene-vinyl 4 Complete Fiber Tear. 5 ASTMD-127.

each to the other being from 0.7 :1 to 1.411, and (c) 5-15% by weight ofdistillate paraffinic wax having a melting point above 150 F.

5. A polymer-containing wax coating composition according to claim 5consisting essentially of 5-17.5% by Weight of ethylene-vinyl acetatecopolymer having an ethylene to vinyl acetate molar ratio from about 8:1to 14:1 and -82.5% by weight of a mixture of petroleum wax basis totalcomposition consisting essentially of (a) 3540% by weight of adistillate paraflinic wax having an ASTM D-87 melting point of -150 F.and which contains no more than about 30% by weight non-normal paratfinsand (b) 35-45% by weight of a residual petroleum wax containing bothmicrocrystalline and high-melting-point parafilnic wax, the residual waxhaving an ASTM D-l27 melting point of at least 160 F., and (c) 10-15% byWeight of a distillate parafiinic wax having an ASTM D-87 melting pointabove F.

6. A polymer-containing wax coating composition according to claim 5consisting essentially of 5-17.5% by weight of ethylene-vinyl acetatecopolymer having an ethylene to vinyl acetate molar ratio from about 8:1to 14:1 and 95-82.5% by weight of a mixture of petroleum wax basis totalcomposition consisting essentially of (a) 35-45% by weight of adistillate paraffinic Wax having an ASTM D-87 melting point of 141-143F. and which contains no more than about 30% by weight non-normalparafiins and (b) 3545% by weight of a residual petroleum wax containingboth microcrystalline and high-melting-point parafiinic wax, theresidual wax having an 1 1 ASTM D-127 melting point of 172-180 F., and10-15% by weight of a distillate paraffinic wax having an ASTM D-87melting point of 158-162 F.

7. A polymer-containing Wax coating composition according to claim 5consisting essentially of 17.5-35% by weight of ethylene-vinyl acetatecopolymer having an ethylene to vinyl acetate molar ratio from about 8:1to 14:1 and 82.5-65% by weight of a mixture of petroleum wax basis totalcomposition consisting essentially of (a) 25-35% by weight of adistillate paraffinic wax having an ASTM D-87 melting point of 135-150F. and which contains no more than about 30% by weight non-normalparaflins and (b) 25-35% by weight of a high-meltingpoint residualparafiinic wax containing both microcrystalline and high-melting-pointparafiinic Wax, the highmelting-point residual parafiinic Wax having anASTM D-127 melting point of at least 160 F., and (c) 10-15% by weight ofa distillate paraflinic wax having an ASTM D-87 melting point above 150F.

8. A polymer-containing Wax coating composition according to claim 5consisting essentially of 5-17.5% by weight of ethylene-vinyl acetatecopolymer having an ethylene to vinyl acetate molar ratio from about 8:1to 14:1 and 95-82.5% by weight of a mixture of petroleum wax basis totalcomposition consisting essentially of (a) 35-45% by Weight of adistillate paraffinic Wax having an ASTM D-87 melting point of 141-143F. and which contains no more than about by weight non-normal parafiinsand (b) -45% by weight of a residual petroleum wax containing bothmicrocrystalline and highmelting-point paraffinic Wax, the residual Waxhaving an ASTM D-127 melting pointof at least F., and (c) 10-15% byweight of a distillate paraflinic wax having an ASTM D-87 melting pointof 15 8-1 62 F.

9. A polymer-containing wax coating composition according to claim 1 inwhich the comonomer is an ester of acrylic acid and a saturatedaliphatic alcohol.

10. The composition of claim 9 in which the comonomer is ethyl acrylate.

11. The composition of claim 9 in which the eomonomer is methylacrylate.

References Cited UNITED STATES PATENTS 2,728,735 12/1955 Anderson260-285 3,060,045 10/1962 Malakoff et a1 106-270 3,175,986 3/1965 Apikoset al. 260-285 3,192,062 6/1965 Arabian et al. 260-285 3,210,305 10/1965Coenen et al 260-285 MORRIS LIEBMAN, Primary Examiner.

B. A. AMERNICK, Assistant Examiner.

1. A POLYMER-CNTAINING WAX COATING COMPOSITION CONSISTING ESSENTIALLY OF5-50% BY WEIGHT OF A COPOLYMER OF ETHYLENE AND A C3-5 COMONOMER SELECTEDFROM THE GROUP CONSISTING OF ESTERS OF TERMINALLY ETHYLENICALLYUNSATURATED CARBOXYLIC ACIDS AND SATURATED ALIPHATIC ALCOHOLS AND ESTERSOF SATURATED MONOCARBOXYLIC ACIDS AND TERMINALLY ETHYLENICALLYUNSATURATED ALIPHATIC ALCOHOLS SAID COMONOMER REPRESENTING 17.4-30% BYWEIGHT OF THE COPOLYMER WHEN THE COMONOMER CONSISTS OF ESERS OFTERMINALLY ETHYLENICALLY UNSATURATED CARBOXYLIC ACIDS AND SATURATEDALIPHATIC ALCOHOLS AND 18-33% BY WEIGHT OF THE COPOLYMER WHEN THECOMONOMER CONSISTS OF ESTERS OF SATURATED MONOCARBOXYLIC ACIDS ANDTERMINALLY ETHYLENICALLY UNSATURATED ALIPHATIC ALCOHOLS, AND 95-50% BYWEIGHT OF A MIXTURE OF PETROLEUM WAX CONSISTING ESSENTIALLY OF (A)ADISTILLATE PARAFFINIC WAX HAVING A MELTING POINT OF 135-150*F. ANDWHICH CONTAINS NO MORE THAN ABOUT 30% BY WEIGHT NON-NORMAL PARAFFINS AND(B) A RESIDUAL PETROLEUM WAX, THE WEIGHT RATIO OF (A) AND (B) EACH TOTHE OTHER BEING FROM 0.7:1 TO 1.4:1, AND (C) 5-15% BY WEIGHT OFDISTILLATE PARAFFINIC WAX HAVING A MELTING POINT ABOVE 150*F. AND WHICHCONTAINS AT LEAST ABOUT 40% BY WEIGHT OF NON-NORMAL PARAFFINS.